URLs and URIs

The URL class is the simplest way for a Java program to locate and retrieve data from the network. You do not need to worry about the details of the protocol being used, the format of the data being retrieved, or how to communicate with the server; you simply tell Java the URL and it gets the data for you. Although Java can only handle a few protocols and content types out of the box, in later chapters you'll learn how to write and install new content and protocol handlers that extend Java's capabilities to include new protocols and new kinds of data. You'll also learn how to open sockets and communicate directly with different kinds of servers. But that's later; for now, let's see how much can be done with a minimum of work.